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Full text of "Lumnite for refractory concrete."

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JUL2 «40 







[BLANK PAGE] 




CCA 



IN TF RNATIONAI 






LUMNITE 



REFRACTORY CONCRETE 



ADVANTAGES OF REFRACTORY CONCRETE 
AGGREGATE 



2 



Refractory Concrete 



Heat Resistant Concrete 



Insulating Concrete 
CONDUCTIVITY — Charts 



Table 



6 



15 



20 



23 



21 



CURING 10 > 16 



DRYING BEFORE USING 
FLOORS — Heat Resistant 



FLUES AND DUCTS 



FOUNDATIONS — Heat Resistant 
HEAT RESISTANT CONCRETE 



HIGH TEMPERATURE FURNACES (2750° F. and Over) 



INSULATING CONCRETE 
INSULATING OVERCOATS 



LOW TEMPERATURE FURNACES (2000° F. and Under) 



MEDIUM TEMPERATURE FURNACES (2000° F.— 2750° F.) 



10 



16 



17 



14 



14 



13 



19 



22 



12 



13 



REFRACTORY CONCRETE — General 



REINFORCING 



SEALING OVENS, KILNS AND FURNACES 



STACKS AND CHIMNEYS 



9 



18 



18 



>|iyrlght i!>4o. . x f i : • — Lnmnlte Cement ( o 



Index 



1 1 1 1 • -« 1 In I > A 




The Atlas TuMNITE. Cement Go. 



United States Steel 




Corporation Subsidiary 



Chrysler Building, New York • 208 South La Salle Street, Chicago 






WHAT is 
Refractory 

Concrete? 



HOW is 
Refractory 
Concrete 
made? 




is 



Refractory 
Concrete 

used? 



Refractory Concrete is a concrete having refractory properties and 
suitable for service at high temperatures in furnaces and other in- 
dustrial heating units. Refractory Concrete has cold strength, as 
placed, similar to that of ordinary structural concrete. After ex- 
posure to service temperatures a fired strength or "ceramic bond" 
is built up by the vitrification of the constituent materials. 



Made with LUMNITE, refractory aggregates and water, Refractory 
Concrete is mixed and placed by methods similar to those employed 
for structural concrete. Furnace walls or other sections may be cast 
in place using forms of wood or steel. Precast units may be made 
and put in service as required without pre-firing. See Pages 6 to 13. 



Economy of installation, maintenance and operation is the primarx 
reason for the rapid extension of the use of Refractory Concrete. 
Materials are readily available. LUMNITE is sold by building 
supply dealers throughout the United States and Canada. Reserve 
stocks are maintained by the Atlas Lumnite Cement Company at 
twelve points in the United States. Aggregate, such as fire brick 
grog, can be prepared from salvaged refractories or may be pur- 
chased from manufacturers of refractories. Stocks of LUMNI1 I 
and aggregates in the plant represent but a small inventory item. 



The adaptability of Refractory Concrete makes possible the ready 
placing of monolithic walls, linings and arches in locations which 



P.M. I - 



Refractory Concrete Arch in 
Annealing Furnace. 

This pre-cast arch, 15 feet 8 inches 
overall length, was hoisted into 
place 24 hours after casting. 




would otherwise require the use of special shapes and entail high 
erection costs. Maintenance is facilitated by a cast-in-place refrac- 
tory or by unfired precast units made to nt the job. The high 24- 
hour strength of LUMNITE concrete makes possible the applica- 
tion of the Kill working load within a day of placing, lor the same 
reason precast units may be handled and installed within 24 hours. 
Opel Iting economy results from the installation of monolithic Re- 
fractory ( oncrete walls — walls without joints. Combinations of 
refractory .\nd insulating sections can be worked out with regard 
only to the desired thermal effects. The designer is not restricted 
by standard sizes of units and conventional wall thicknesses. 




REFRACTORY CONCRETE 
Doors for Core and Mold Drying 
Ovens in a Steel Foundry. 



Pag i 3 




Heat Resistant 
Concrete 



Insulating 
Concrete 



Refractory Concrete Roof Slab for 

Pit Annealing Furnace. 
This roof slab had been in service 
about two years when the picture 
was taken. 



Page 4 



LUMNITE concrete exposed to temperatures which cause the dis- 
integration of ordinary concrete is known as Heat Resistant Con- 
crete when the temperatures are not high enough to vitrify the 
material and form a ceramic bond. Furnace foundations, ducts 
carrying hot gases and floors subject to soaking heat are typical 
examples of Heat Resistant Concrete. Where ordinary structural 
concrete either cannot be used or does not have an economic life, 
concrete made with LUMNITE and suitable aggregates combines 
structural strength and resistance to heat. See Page 14. 

Insulating Concrete is essentially Heat Resistant Concrete with low 
thermal conductivity. Several special aggregates are commercially 
available for making light-weight concrete with excellent insulating 
properties. The type of aggregate selected depends on the thermal 
conductivity and heat storage capacity desired in the Insulating 
Concrete. LUMNITE is used as the binder for the special aggregates 
because the concrete must be stable under high temperatures. 

Insulating and refractory characteristics may be obtained together 
through the use of such aggregates as refractory-insulating-fire- 
brick grog or other special materials. See Page 19. 



These three types of concrete — Refractory, Heat Resistant, Insul- 
ating — provide for a wide range of thermal conditions. All are made 
with LUMNITE and aggregates selected according to the require- 
ments of the particular installation. With LUMNITE in stock and 
a supply of low-cosc aggregates, materials are available for a great 
variety of furnace construction and maintenance jobs. 



Refractory Concrete Car Top 
and Baffles for Car Type 
Annealing Furnace. 
This furnace also has precast Re- 
fractory Concrete roof arch sec- 
tions with span of about 14 feet 
6 inches. 




LUMNITE when mixed with water sets and hardens by chemical 
action without the application of heat. It is used 03 the binder tor 
refractory, heat resistant and insulating aggregates in the making 
of these several kinds of concrete. 



Characteristics 

of 
LUMNITE 



Coiicretl made with LUMNI'I'l. ind suitable a^re^tes has the 
property ot retaining i considerable part of its cold strength ifter 

contimi I exposure at high temperatures. l.UMNITl is not m it- 



h refractory material. It is used in making Refractor) Con- 

rel I" tUSC its efleCtiveneSI as a binder is not destroxed by the 

serv ice temperal in es. 



I I'MNIII Is not a Portland cement ami it diHcrs from Portland 

cerium in chemical composition and physical properties. LUMNI I I 



is .1 IK mm 



lei 



aluminate cement .is distinguished rrom portland in 
which the principal constituent! are calcium sili itcs. I he calcium 
luminatc cementa arc the only commercial hydraulic cementi m men 

have heat resistant properties required fof Ketractorv < micretc. 
I UMNTl I is the only caicium alumm..u cment m.iJc in America. 




LUMNI I"! ( onu-tte Used to Insulate 
Floor Slab .ind Burner Ports of 

Oil Still Furnace. 

LLMNITt slab is placed over ordi- 
nary concrete foundation. Note ven- 
tilating ducts through floor slab. 



Pagi 5 



Refractory 
Properties 



Aggregate 
Selection 



METH 



MAK 



REFRACTORY CONCRETE 



The proportioning of mixes and grading of aggregates for Refrac- 
tory Concrete differ in principle and practice from those employed 
for structural concrete. The manipulation of LUMNITE also dif- 
fers from that of ordinary structural cements. On the following 
pages we give suggestions for making Refractory Concrete suitable 
for several kinds of service. Great diversity in operating conditions 
and service requirements makes it difficult, if not impossible, to lay 
down hard and fast rules for formulating mixes. In general, the 
suggestions are based on satisfactory installations made by users of 

Refractory Concrete. 



LUMNITE may be used as a binder with acid, basic or neutral re- 
fractory aggregates. The refractory properties of the concrete de- 
pend on the aggregate. These properties are not necessarily the same 
as those of the aggregate in its original state. In general, the insu- 
lating value of Refractory Concrete will be somewhat greater than 
that of the refractory material with which the concrete is made. 
The refractory limit will be slightly lower than that of the aggre- 
gate. Refractory Concrete has consistently shown excellent non- 
spalling characteristics in tests and in service. 



Selection of aggregate depends on service conditions and availability. 
On Pages 12 and 13 those which may be used within certain tem- 
perature ranges are listed under the classifications: 



2000° F. and under 



Low Temperature Furnaces 

Medium Temperature Furnaces 

High Temperature Furnaces 2750° F. and over 



2000°F.-2750° F. 



Page 6 



Particle size and grading of aggregate are of the greatest importance. 
Regardless of type, the aggregate should range from the maximum 
size particles through all intermediate sizes down to and including 
fines and dust. Maximum size may be %" to 1 J4" depending on 
thickness of section. When large sizes are not available aggregate 
of smaller maximum size may be used. 

Approximately 5 0% of total aggregate should pass a /g" screen. 
IS', to 18% should pass a 100 mesh screen. If necessary add fines 
to original crushing. Uniform grading is required in any case, i.e., 
there must be intermediate sizes between the fine and the coarse 
particles. 



When accurate sizing is impracticable an ordinary lly screen may 
be used. 3 5% of the total aggregate should pass the fly screen. Uni- 
formity of grading can be determined visually by the presence of 
all particle sizes between fines and coarse. 

(arc should be taken to avoid mixing the clay fire brick with other 
kinds of bricks, such as common or silica brick. Old mortar and 
cements adhering to the brick should be cleaned off to prevent con- 
tamination of the LUMNTTE. 



Service temperature determines proportions of mix. Proportions 
for the several temperature ranges arc given on Pages 12 and 13. 



Slow Cooling Pit for Steel Billets. 
LUMNITE Refractory Concrete 
used for walls and bottom. Arched 
cover lined with LUMNITE Insu- 
lating Refractory Concrete to re- 
duce weight and heat loss. 



Aggregate 

Size and 
Grading 



Proportions 



Page 7 




Proportioning 



Molds 

and 

Forms 



IS 8 



Accurate measurement of binder and aggregate is important. One 



LUMN 



Wh 



be weighed. For example— if one cubic foot of Refractory Concrete 

6 r one Font 




aggregate using 



is desired, using a 1:4 mix, measure 
cubic foot box, weigh out 23 ^ pounds of LUMNITE. Weigh the 
LUMNITE, do not measure in the cubic foot box. A finely divided 
material, such as LUMNITE, cannot be accurately measured by 
volume. It should be weighed when a fraction of a bag is needed. 



All proportions are stated in terms of total aggregate. When two 
or more sizes are used to obtain proper gradation, proportions given 
in this book refer to quantities of aggregate after mixing together 
the two or more sizes. 



I or most types of installations forms similar to those employed in 
concrete construction arc used. Many fire doors because of their 
shape do not need any side molds or forms. When it is desired to 
have the lining thicker than the side flanges of the door, wooden 
forms or molds can be made to give the desired thickness ot the 
lining. It is sn jested that such forms be made with Ul inside taper 
and greased so they can be easily removed. If tapered sides are 



Gis Gun Blocks for Coke Ovens 
An\ special shape may be made at 
the plant required. Refractory 

properties are the same as cast- 
m-place Refractory Concrete. 



Precast Refractory Concrete Shapes 
The rapid hardening of LUMNITE 
facilitates the casting of special 
hapes. They may be 1> idled and 
installed the day after making. 




objectionable the corners of the wooden 
form may be fastened with screws or 
bolts for easy removal. 



Metal reinforcement cannot be used in 
Refractory Concrete in the same man- 
ner as in ordinary structural concrete. 
At high temperatures carbon steel loses 
strength and disrupts the concrete. 
Heat-resistant steels have given better 
results. Special methods of design are 
required when Refractory Concrete is 
to be used for structural purposes. In- 
formation on this subject may be ob- 
tained from the Atlas Lumnite Cement 
Company, 13 5 East 42nd Street, New 
York, N. Y. 



When mixing Refractory Concrete 
first moisten the aggregate until it will 
not readily absorb any more water, 
then add the LUMNITE and mix to a 
uniform color. 




LUMNITE Refractory 
Concrete Coke Oven Door 

Lining 

This photograph was taken 
after the lining had been 
in continuous service for 
more than 5 years. 



Add sufficient cold water, not over 80° F., to make the mixture 
plastic, soft and sticky. If the aggregate contains sufficient fines 
and dust the mix will be plastic, easily placed by spading without 
ramming, and will not release free water. If the aggregate contains 
insufficient fines and dust to produce this consistency, the addition 
of small percentages of plastic fire clay will increase the plasticity. 
Fire brick aggregates will require a longer period of mixing than 
ordinary concrete aggregates in order to permit complete absorp- 
tion of the water. Should the mix become dry during placing add 
more water and remix. 




Mixing 



Page 9 



Placing 



weakness. For 



Curing 



Drying 
Before 
Using 



example, if a door is being lined which requires three batches, place 



com 






the next batch for the second third of the area for the complete 
depth; the next batch to cover the last third of the area for the 
complete depth. The concrete should be spaded to densify and con- 
solidate it. If a smooth surface is desired use only a wood float. A 
cement gun is sometimes used for placing refractory mortars. 

Best results are obta.ned if the exposed surface of the concrete b 
kept moist by sprinkling from six hours after mixing until twenty 
hours after mixing. This is of particular importance when dense 
aggregates are used, or the work is done in a place where high atmos- 
pheric temperatures prevail or where the air is very dry. 

The rapid hardening of 1 UMNITE greatl) aids the drying of Re- 
fractor) < terete linings. Predrying is important in work of con- 
iiderabk man. If the concrete is to be subjected to high tempera- 



i \ 




I'rccast LUMNITE 
Refractory Concrete 
Front Arches in Forge 

Furnace 
An example of Re- 
fractory Concrete m 
unusually severe 
set I ice. The um <>1 
precast units facili- 
tates replacement and 
m.untenance. 



Aggregate and mol 
used in making th 
precast arch section 
shown m the abov 
picture. From left t 
right, grog pile, arc 
section on end, she* 
steel mold, end vie^ 
of arch section. 




REFRACTORY CONCRETE TOPS FOR TUNNEL KILN CARS 

The group of cars in the picture is part of the equipment of 50 cars, all topped 

with Refractory Concrete, in use at one tile plant. 



tures suddenly, as in the case of many door linings, better results 
will be secured if 48 to 60 hours elapse before the lining is put into 
service. When it is desirable to use the linings before this period a 
small amount of artificial drying may be necessary. The same care 
when first heating Refractory Concrete is required as when using 
other refractories. 



When Refractory Concrete is heated on all sides, there is a noticeable 
shrinkage which is offset to a considerable extent (not entirely) by 
a small thermal expansion. When heated only on one side, shrinkage 
may develop hair cracks on the hot face or a few cracks extending 
into the concrete. 



In each case, the thermal expansion of the materials while hot prac- 
tically compensates for the initial shrinkage. In lining a furnace 
door, for example, the frame is filled with concrete. No allowance 
is made for expansion of the concrete. 



Expansion 

and 

Contraction 



Page 1 1 



Proportioning and Materials for Low 



J 



■ 






Low Temperature Service 2000° F. and Under 



Proportions 



1:4 



( 1 bag LUMNITE to 4 cu. ft. of aggregate) . 
Note— 1 bag LUMNITE=1 cu. it. =94 lbs. 



See "Proportioning," Page 8. 

A one bag batch of 1:4 mix will yield ap- 
proximately four cubic feet of Refractory 
Concrete. 

The load-bearing capacity of Refractory 
Concrete in service at 2000° F. and under 
will be increased with a somewhat richer 
mix. A 1 : 3 mix should be used where heavy 
loads will be imposed directly on the Re- 
fractory Concrete. This condition holds for 
some ceramic kiln car tops and some anneal- 
ing furnace car tops wnere heavy ware and 



castings are 



fired. 



Aggregate 

Fire Clay Grog 

Refractory Insulating 
Firebrick Grog (RIFB) 

Crushed Firebrick 

Crushed Insulating Brick 

Crushed Pottery Saggers 

Light Weight Refractory 
Aggregate (LWR)* 

Olivine 

Diatomaceous Silicaf (Service 

Maximum 1800° F.) 

When both insulating and refractory prop- 
erties are desired vermiculite may be used 
in combination with the fireclay and LWR 
aggregates. The addition of vermiculite in- 
creases the insulating value but decreases the 
strength and resistance to abrasion. 

:: Such as Gravelite, Haydite, Raylite 
tSuch as Sil-o-cel C-3 



< 



ANNEALING FURNACE CAR TOP 



A Refractory Concrete top 40 feet long, 12 feet wide, cast in place. 




Page 1 2 



Medium Temperature Service 2000° F. to 2750° F 



Proportions 



Service Temperature 

2000 F.-2250 F. 
2250 F.-2500 F. 
2500°F.-2750° F. 



LUMNITE: Aggregate 
Bags Cubic Feet 



1 
1 
1 



5 
6 

7 



Certain installations may require the aggre- 
gates suggested for high temperature fur- 
naces. 

When aggregates recommended for high 
temperature furnaces are used for medium 
temperature furnaces a 1:6 mix should be 
used . 



Aggregate 
Fire Clay Grog 

Refractory Insulating Firebrick Grog 
Crushed Firebrick 
Crushed Pottery Saggers 

ohvi 



For service between 2500° F. and 2750 I 
IggregatC should ha\e | softening point oi 

Cone 30 or higher. 

""Maximum service temperature t<>r am 
Rll'h grog should be obtained h<>m the 

manufacturer. 



High Temperature Service 2750° F. and Over 



Proportions 

1 bag LUMNITE to 6 or 7 cu. h. of aggre- 
gate. 

When Olivine is used in high tempcratur 

service it is desirable, and in mo t asea tu »- 

sary, to remove the material passing a %" 
screen and substitute tines oi one 01 the 

ills, preferablv chromite. A mix 



Aggregate 



K.U1MU 



Ch 



romi 



other 

of 1 bag of LUMNITE, 4 cubic teet chro- 
mite or fused alumina, graded from \ to 
dust, and 4 cubic feet of Olivine, graded 

tnini I /4 " to %" or ! W% ls suggested 



Diasporc 

I used Alumina 

Kyanitc 

Magnesite 

Mullite 

{ )livme 
Sdhmanite 



SUMMARY OF REFRACTORY CONCRETE Ml XI s 



FURNACE 
TEMPERATURES 



Up to 2000 F. 
2000 F. to 2250 F. 
2250 F. to 2500° F. 



PROPORTION 



LUMNITE 
(bags) 



1 
1 
1 



2500° F. to 2750 F. 



Above 2750 F. 



I 



Aggregates 

(Cu. Ft.) 

4 
5 

6 



KINO OF AGC.KH.ATr. 



to 7 



1 



6 to 7 



Clay aggregates; olivine 

Clay aggregates; olivine 

Clay aggregates; olivine; 
spen.il aggregates* 

Clay aggregates; olivine; 
special aggregates* 

Special aggregates* 



*Sce list under "High Temperature Service" 



LUMNITE 

per cu. yd 

of Refractorv 

Concrete 
6.75 

5.40 

4.50 



4.5o 

to 

3.8 



I'AGI I 




The disintegration of ordinary concrete by continued exposure to 
high temperatures creates a serious problem in the construction of 
furnace foundations. Floors under and around furnaces, ducts and 
flues carrying hot gases are subject to the same destructive effect. 

Experience has shown that LUMNITE concrete when made with 
suitable aggregates offers a much greater degree of resistance to the 
disintegrating effect of "soaking heat." Although the strength of 
all concrete is lowered by continuous exposure to heat, many of the 
advantages of concrete construction are retained in LUMNITE 
Heat Resistant Concrete. 

For Heat Resistant Concrete, materials which release lime must not 
be used. LUMNITE is the only American-made hydraulic cement 
which does not release lime during the hardening period or after 
the concrete has been exposed to heat. 



Design 



Heat Resistant Foundations 

Proper design of the foundation will facilitate its construction with 
LUMNITE concrete and extend its service life. In all cases the 
foundation should be so constructed as to dissipate the heat which 
is built up in the mass of concrete exposed to the high temperatures. 
Ventilating ducts through the concrete will assist such dissipation. 
This ventilation also aids in carrying off the heat generated by the 
hydration of the LUMNITE. The hardening action of LUMNITE, 
on account of its rapidity, causes the evolution of considerable heat 
during the first 24 hours after the concrete is mixed. 

Heat Resistant and Insulating Concrete, in combination, are some- 
times used in furnace construction. An insulating slab, similar to 
that shown in the picture at the bottom of Page 5 is placed on a heat 
resistant foundation. Heat Resistant Concrete is employed when 
it is expected that relatively high temperatures will eventually be 
built up in the foundation during continuous operation of the 



fu 



rnace. 



Page 1 4 



HEAT RESISTANT CONCRETE 

Construction view of LUMNITE 
concrete slab to support regenera- 
tor walls of underburner regenera- 
tive by-product coke ovens. 




Old fire brick, paving brick or hard-burned common brick, when 

crushed to the required sizes, will be found more satisfactory than 

sand and gravel which are often high in silica. Trap rock, both fines 

and coarse, may be used. 

Light-weight refractory aggregates, such as Gravelite, Haydite and 

Raylite, are suitable especially where insulation is desired. Air-cooled 

blast furnace slag has been used at temperatures below 1000° F. 

Slag is not recommended above that temperature. 

Lime-releasing aggregates should be avoided. Materials such as silica 

aggregates which undergo sudden volume change when heated must 

not be used. 

The coarse aggregate should be retained on a screen having round 

openings of l / 4 ". The maximum size particle may be from %" to 

1 y 2 ". The fine aggregate should pass a l / 4 " round opening and have 

some fines passing a 100 mesh sieve. 

1 bag (1 cu. ft.) of LUMNITE, 2j/ 2 cu. ft. fine aggregate, and 

iy 2 cu. ft. of coarse aggregate. If the mix is harsh, increase the fine 

aggregate and decrease the coarse aggregate in equal proportions. 



With 



Lime 



ticity must not be used with LUMITE. 

LUMNITE concrete is placed in the same manner as ordinary con- 
crete. When large masses of LUMNITE concrete are desired it may 
be advisable to place them in more than one operation. In general 
the thickness of a large slab placed at one time should not be greater 
than 1 5 inches, unless special provision is made for curing. When a 
large mass of concrete is placed in two layers 24 hours should be 
allowed for the curing of the first layers before the concrete for 
the second layer is placed. 



Aggregate 



Proportions 



Placing 



Page 1 5 



Curing 






Aggregate 



Proportions 



Placing 



Pag i 16 



After the concrete has set (from 6 to 10 hours after placing, de- 
pending on atmospheric conditions and temperature of concrete 
when placed) the concrete should be kept moist by sprinkling with 
water until it is 24 hours old. The time for first application of 
curing water may be determined by rubbing the surface with a 
moistened finger. If the finger is clean after the rubbing, sprinkling 
should start. If the finger is soiled by the test, sprinkling should be 
withheld. 



Floors Exposed to Direct or Indirect Heat 

For best results a monolithic, one course heat resistant floor should 
be placed. Thin heat resistant top courses on ordinary concrete base 
slabs are not recommended. 

Floors continuously exposed to high temperatures do not have the 
wearing quality of ordinary, unheated concrete. They cannot be 
expected to withstand abrasion from trucking, dragging of skids or 
other severe wear. 

Crushed old firebrick, paving brick or hard-burned common brick 
may be used. Trap rock, fine and coarse, is also satisfactory. The 
harder aggregates will give a better wearing surface. Light weight 
refractory aggregates are serviceable from standpoint of heat resis- 
tance but should not be used for floors subject to traffic. 

A mix of 1 bag LUMNITE, 2 l / 2 cu. ft. fine aggregate, 2 l / 2 cu. ft. 
coarse aggregate is generally satisfactory. The mix may be adjusted 
as described under "Heat Resistant Foundations" to improve work- 
ability for placing and finishing. 

All operations in placing LUMNITE Heat Resistant Floors, except 
as noted above, are the same as for LUMNITE concrete floors for 
the usual structural purposes. Full information on this subject will 
be found in the pamphlet "LUMNITE for Structural Concrete." 



Heat Resistant Con- 
crete Foundation for 
Foundry Cupola. 

A slab approximately 
six inches thick was 
placed over ordinary 
concrete foundation. 




Billet Heating Furnace erected on 
LUMNITE Heat Resistant Con- 
crete slab. The three furnace doors 
are lined with Refractory Concrete 




Flues and Ducts 



LUMNITE Heat Resistant Concrete is an adaptable material for 
the construction of ducts carrying hot gases. Many satisfactory in- 
stallations have been made, especially in oil refineries. 

Several types of duct have been developed by LUMNITE users. 
Monolithic LUMNITE concrete structures have been built in some 
cases. In others precast sections are used. LUMNITE protective 
linings have been placed in ducts built of reinforced portland ce- 
ment concrete. Where ducts are placed partially underground or 
where dissipation of heat is inadequate, it is desirable to provide 
ventilating flues in the concrete. One convenient method is to con- 
nect the ventilating flues into the chimney. The draft will provide 
a continuous flow of air to carry off the heat and reduce the heat 
storage in the concrete. 

The light-weight clay aggregates are in general use for these 
LUMNITE concrete ducts. The concrete has adequate structural 
strength, low heat storage capacity and high insulating value. (See 
information on Insulating Concrete on following pages.) 



LUMNITE is not a portland cement. Methods of use are somewhat 
different from portland cement practice, especially in curing pro- 
cedure. The pamphlet "LUMNITE for Structural Concrete" should 
be studied carefully before constructing foundations or floors of 
Heat Resistant Concrete. 



Design 



Aggregate 



Caution 



Page 17 



Mixes 



Aggregate 



Application 







nature as 



Sealing Ovens, Kilns, and Furnaces 

Prevention of infiltration of air in ovens, kilns and furnaces is of 
prime importance in many industr.es. When the equipment .s ex- 
posed to the elements it must be sealed against the entrance of water 
,s well as air. LUMNITE mixtures have been used for sealing such 
units with satisfactory results, both on sheltered equ.pment and on 
that exposed to wind and rain. 

The mixes used approximate one part LUMNITE to 2J4 parts 
aggregate graded from / 8 " or 3/16" maximum size, down to and 
including fine particles. For application with a trowel sufficient 
water should be added to give a plastic mix. For cement gun work 
the amount of mixing water will be controlled by the operation of 
the gun. 
The aggregate used with LUMNITE should be of the same general 

the brick to which the mortar is applied. For example, on 

clay fire brick, ground clay fire brick or Haydite can be used as 
the aggregate. On silica brick, silica sand should be used. 
The wall should be cleaned of all dirt and loose particles. When the 
temperature of the surface of the wall to which the mortar is to 
be applied is 200 ° F. or lower, the brick wall should be moistened 
before the mortar is applied. At temperatures above 200° F. it is 
doubtful if the wall can be successfully moistened. 
Particularly on vertical or hot walls the use of a cement gun for 
applying the mortar will be of great help in obtaining the best re- 
sults^ When no cement gun is available the mortar may be applied 
by troweling. The seal coat is usually from l / 2 " to %" thick. 

Sprinkling of the LUM? 

Under ordinary conditions at atmospheric temperatures the set will 
occur in 6 to 8 hours after placing. When the mortar is applied to 
hot walls the set will be speeded up. The test and directions 
for curing on Page 16 should be followed. 



ITE 



k 




Stacks and Chimneys 

LUMNITE is widely used for protective linings of steel stacks and 
for mortar in brick and tile chimneys. In addition to refractory 
properties LUMNITE mortar is resistant to the corrosive action of 
chimney gases. 

A special illustrated folder, "LUMNITE in Stacks and Chimneys," 
describes these uses. 

A Typical Industrial Stack with 
LUMNITE Refractory, Insulating, 
Corrosion Resistant Lining. Same 
type of lining used in boiler 
breechings. 

Pagk 1 8 



INSULATING 




Insulating Concrete is a special type of Heat Resistant Concrete. It 
may also have refractory properties, in which case it is essentially 
Refractory Concrete of low thermal conductivity. Insulating Con- 
crete made with certain aggregates has structural strength greater 
than that of most walls laid up with the usual insulating brick. 



Structural strength and low thermal conductivity make possible the 
use of Insulating Concrete as a back-up to Refractory Concrete or 
other refractories. The Insulating Concrete gives added strength 
to the wall. It can be used in many cases to replace both insulating 
brick and the outer layer of common brick. Higher insulating value, 
lower heat storage, ample strength, reduced dead load and lower 
initial cost result from the use of Insulating Concrete in this manner. 



Steel jackets can often be eliminated when Insulating Concrete is 
used for outside walls of furnaces. The walls may be reinforced 
with angles or T-irons. One flange is embedded in the concrete 
and the other flange (or flanges of T-iron) is exposed to the air 
on the outside of the wall. The embedded flange should not extend 
more than halfway through the thickness of the Insulating Con- 
crete. This reinforcing will greatly increase the structural strength 
of the outside walls, eliminating the more expensive method of 
jacketing the furnace with steel sheets or plates. 

Furnace walls of Insulating Concrete may be built without a fire 
brick inner lining when the concrete is made with suitable aggre- 
gates. Monolithic walls with few or no joints are more efficient in 
operation than brick masonry walls with many joints. A surface 
wash or coating on the inside of the furnace is seldom necessary 
when the higher-strength, light-weight, clay aggregates are used. 

Refractory-Insulating Concrete is made, with LUMNITE, at about 
the same cost as ordinary Refractory Concrete. A monolithic Re- 
fractory-Insulating Concrete wall or roof arch can usually be built 
at a cost comparable with plain refractory construction. 



Design 



Refractory- 
Insulating 
Concrete 



Page 1 9 





Annealing Furnace Cover lined 
with Refractory Concrete. A 

lining 12 



jointless, cas 



t-in-pl 



feet in diameter. 



Aggregates 
for Insulating 
Concrete 



The aggregate for Insulating Concrete should be as strong struc- 
turally as possible without sacrifice of the required insulating value. 
Strong structural concrete cannot be made with structurally weak 



Where 



obtained through the use of the more efficient, but structurally 
weaker, insulating aggregates. Combinations of aggregates can be 
used to produce concrete having the highest insulating value con- 
sistent with the structural strength required for any particular in- 
stallation. 

Aggregates commonly used for Insulating Concrete at temperatures 
up to 2000° F. include: Gravelite, Haydite, Raylite, Sil-o-cel, ver- 
miculite, The first three are light-weight processed aggregates of 
relatively high strength. Sil-o-cel is one of a number of diatomaceous 
aggregates of medium strength. 

Vermiculite is an exfoliated mica of low strength marketed under 
various trade names, one of which is Zonolite. With vermiculite mixes 
the concrete should be compacted after placing to secure greater 
strength. Degree of compaction depends on proportion of vermicu- 
lite used. Conductivities of several mixes of vermiculite with other 
insulating aggregates are given in the table on Page 21. It is also used 
in combination with crushed firebrick. 

In temperatures above 2000 F. several light-weight aggregates made 
from fire clay are available. (These are generally known as insu- 
lating fire brick grogs. ) The names of manufacturers and producers 
of these special aggregates can be obtained from The Atlas Lummte 
Cement Company. 



Page 20 



LUMNITE Heat Resistant — Insulating Concrete is used 
extensively in Oil Refinery Construction. 

LUMNITE concrete made with a light-weight clay aggre- 
gate is used for insulating tube sheets, tube header com- 
partments and air-cooled floor slab in the Oil Still Furnace 
pictured in the foreground. 

LUMNITE concrete slabs are also placed at the top of 
heaters of this type to act as insulation and provide an 
upper working floor. 



Proportions of LUMNITE and one or more aggregates vary over a 
wide range. They depend on the required insulating value (thermal 
conductivity) and on the desired structural strength. Mixes such 
as those tabulated below are in common use. 



LUMNITE 

Sacks 



1 
1 
1 



AGGREGATE 



Cubic Feet 



Type 



H \C M 



Conductivity "K 
B.T.U./sq. ft./in./°F. hr 



4 Light wt. clay Agg. 

5 Light wt. clay Agg. 

6 Light wt. clay Agg. 



1 



1 



4 

2 



Light wt. clay Agg* 
Vermiculite 



1 



_j 



3 Light wt. clay Agg 

3 Vermiculite 

2 Light wt. clay Agg 

4 Vermiculite 

6 Vermiculite 



3.5 
3.25 



3.0 



2.5 



2.25 



2.0 



1.5 



si- 



Approximate values at 1500 F. Mean Temperature 



The mixes are tabulated in the order of structural strength, the 
strongest (1:4 with clay aggregate) at the top, the weakest (1:6 
with vermiculite) at the bottom. 

Details of mixing, placing and curing Insulating Concrete are the 
same as for Refractory Concrete, see Pages 9 to 11. 




Proportions 
for Insulating 
Concrete 



Page 2 I 







Placing 



Aggregate 



Proportions 



l>\<,i :: 



Bulkhead of Open Hearth Furnace. 
LUMNITE Insulating Concrete ap- 
plied with a cement gun. Note 
sheet metal supports inserted at 
every fourth joint. 



Insulating Over-Coats 

Insulation applied to a cold furnace frequently is cracked 
by expansion when the furnace is heated. Infiltration of 
air through the cracks reduces the efficiency of the furnace 

and increases operating costs. Application of an insulating overcoat 

to the hot furnace prevents this infiltration to a large extent. 

LUMNITE insulating mixes applied with a cement gun solve the 

problem of placing insulation on a hot furnace. 

The application can be made while the furnace is in operation. The 
refractory insulating materials are expanded by the heat of the 
furnace when the mixture is applied. Cooling of the furnace further 
compresses the insulation , which s hould have sufficient resilience to 
minimize cracking. The insulation may be built up to any desired 
thickness by shooting on successive coats. 

Any of the aggregates suggested for Insulating Concrete may be 
used with LUMNITE for application with a cement gun. Aggre- 
gate should be selected in accordance with the temperature condi- 
tions, size and grading being determined by the requirements of 
cement gun work. 

Suitable proportions have been worked out in the field by a number 
>f users of these LUMNITE mixtures for their special purposes. 
Proportions will vary with aggregates used and working conditions. 
Mixtures as lean as 1 bag of LUMNITE to 10 cubic feet of aggre- 
gate have been applied successfully. If greater strength is needed 
the mix may be as rich as 1 bag of LUMNITE to 5 cubic feet of 
aggregate. With the leaner mixtures it may be necessary to add a 
small amount of fireclay to provide necessary adhesiveness and pre- 
vent excessive rebound. 



ME A N TEMPERA TUR> 



1000 



1250 



1500 



1750 



2000 



LUMNI 



* 



• 



• 




RIFB— REFRACTORY INSULATING FIREBRICK 

GROG 
LWR — TYPICAL LIGHT WEIGHT REFRACTORY 

AGGREGA TES 



(L 



CONDUC Tl VI TY CHART 




Conductivity Chart No. 2 

The curves were prepared from data 
obtained from a number of manufac- 
turers and other sources. The several 
aggregates are believed to be typical of 
those in their respective classes* 



Conductivity Chart No. 1 



These Conductivity Charts show com- 
parative insulating values of several 
types of Refractory Concrete and other 
materials. 



MEAN TEMPERATURE V 



CONDUCTIVITY CHART H 





500 tOOO 


1500 


2000 




2500 




r 








^ 








19 
















19 




h- 




' 












IB 
















19 




















17 
















IT 




















16 
















(6 




















15 1 




1 _ 












15 




CCNCRETf- 


MADE * 


f7!y 












14 A 


/ L OMNI ra ■ FINE 1 1lk)kE l 








(4 




' CCAJSE O 


L/lrie 














13 Aj 














ti 




















* 


12 
















* (2 


k. 


L- = — — — — ' — 




cim 


M 9 ^l ^^J^^^r M & 










U_ 




V 




r 






II 














■ 






k 


to 

LV 


















•/so. 














9 1 L 
















9 


% 




















k. 


8 C 


LAY riREBRlCkS 












9 
















u> 


7 














7 




















6 


- Am 


frp/r — kj 


SF/Vj 5fkj$Hi 








6 




*- ' / ifet 


ffirU^AEGA 








5 














5 


















4 /A Si h 


LJ7M? FtJBBl 












4 




















5 














J 
















2 




INC Fit 


?> V6 CRPS Hi 








2 




L INSULL 7 


u bi m nr 


JS 








/ 




TV r£ 












I 


■ 





















± ± 












\ 


I Q 






Pace 2 i 



Temperature 

Conversion 

Chart 



l>\t,E 24 






o 



u 

O 





^ht 



01 ^ 




Da.q.F 

3400 


/S7/ 


Ocy.F 
3333 


Cono. 

33 


0*0. C 

/833 


0<uj.f 

3272 


Da-Q C 

/800 


3300 


J&/5.3 


3790 


3G 


/8/0 


3700 


/7GO 


3243 


33 


778$ 


3092 


7700 


3/73 


33 


/745 


3/CO 


77 03 


3092 


32 


/700 


3000 


7G483 


3oo2 


30 


7G30 


2972 


/GOO 


7900 


/393 


7934 


73 


/G/3 


7A7G 


23 /^an 




2800 


Z337.3 


4 O? / *y 

273 G 


2o 


7330 


2732 


7300 


2700 


7483 


27 /a 


78 


7490 


2Goo 


742G.3 


7G09 


/G 


74G3 


2332 


/doo 


7G/3 


73 


/433 


23oo 


737/ 


2**2 


74 


/doo 


2402 


73 


/330 


2372 


/30P 


2400 


73 /3. 3 


24/7 


// 


/32S 


2343 


9 


/783 


7300 


7260 


2/92 


/700 


2 300 


8 


/2G0 


7200 


7204 


274G 





/730 


220/ 


3 


/703 


2/00 


7/44 


7/38 


3 


//JO 


20/2 


//OO 


7 09 3 


0/ 


7/43 


2000 


/093 


7039 


03 


///3 


7940 


04 


/OGO 


/900 


/03& 


/832 


/OOO 


7904 


03 


/040 


/gOO 

/700 


CtJ**? 


78/4 


07 


990 


3AZ — 

97G 


7742 


08 


930 


/G32 


9oO 


/70G 


09 


930 


/GOO 


877 


/GOT 


0/2 


873 


7472 


SOO 


/300 


**^ ^ . 

87G 


/32G 


0/4 


830 


/403 


O/O 


793 


/doo 


7 GO 


/323 


0/& 


720 


7792 


TOO 


/300 


\704 


/707 


020 


G30 


/700 


G48.3 


///7 


— L 

Goo 


//oo 


393 


//7/ 


022 


G03 


/OOC 


537-8 


Cons, 


u /icafac/ 

/30*C 


932 


300 











c 






jo 

«/1 



<u o 



oc ■* 



u at 




E E I 




Service ranges of several types of Refractory Concrete are indicated on the 
left side of the chart. Service ranges for a number of Insulating Concretes 
are shown on the right. 



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